Test Predicts Walking Problems with Artery Disease

A simple test called the ankle brachial index (ABI) can help predict future walking problems in patients with peripheral arterial disease, a condition that involves hardening of the blood vessels in the legs and elsewhere, new research shows.

A simple test called the ankle brachial index (ABI) can help predict future walking problems in patients with peripheral arterial disease, a condition that involves hardening of the blood vessels in the legs and elsewhere, new research shows. The ABI, which can be determined in just a few minutes with standard equipment, is the ratio of the blood pressure in the ankle to the pressure in the arm. Any value below 1 is considered abnormal and values below 0.25 indicate severe blood flow problems that could result in amputation of the leg if left untreated. Previous reports have shown that the ABI and leg symptoms correlate with a person’s current walking status. However, it was unclear whether these parameters could be used to gauge future functional impairment. To investigate, Dr. Mary McGrae McDermott, from Northwestern University Feinberg School of Medicine in Chicago, and colleagues evaluated the outcomes of 676 subjects who had walking tests performed when the study began and 1 to 2 years later. Of the participants, 417 had peripheral arterial disease and 259 did not. The ABI, coupled with leg symptoms, predicted how far and how fast patients with artery disease would be able to walk in the coming years. Compared with subjects without artery disease, patients with persistent leg pain experienced greater annual declines in walking distance and speed. Even in the absence of symptoms, peripheral artery disease was associated with an increased risk for becoming unable to walk continuously for 6 minutes. “Our findings underscore the importance of using the ABI to identify persons with peripheral arterial disease, since (it) is frequently undiagnosed ” or symptomless, the authors note. (SOURCE: Journal of the American Medical Association: Reuters Health News: July 2004.)